Dispenser cap and method of making same



3, 1939. A. w. sum. '51- AL 2,175,052

DISPENSER CAP AND METHOD OF MAKING SAME Filed Sept. 2. 1938 INVENTURS ARTHUR V BULL HER! S C M. LOMAN y CORYDON M. GRAFTON 147 I ATTORNEYS.

Patented Oct. 3, 1939 2,175,052 DISPENSER CAP ANSD METHOD OF MAKING Arthur W. Bull, Grosse Pointe, and Cheri M. 810-- man and Corydon M. Grafton, Detroit, Mich, assignors, by mesne assignments, to United :States Rubber Company, New corporation of New Jersey York, N. 32., a

Application September 2, 1938, Serial No. 228,106

8 .Claims.

Our invention relates to an improved closure for receptacles and a method of making same,

- and in particular it relates to a dispensing closure for attachment with containers such as for toothpaste, shaving cream, and the like to which internal pressure is applied to discharge the contents therefrom.

In general, the invention comprises a cap having a flexible, stretchable resilient member for attachment to the end of a dispensing container, the member being so constructed and proportioned that, at least during operation, stresses and strains in the resilient member are directed toward the central end portion of the cap, thereby tending to maintain an aperture through the central end portion in a normally closed state.

Dispensing containers such as tubes for toothpaste and shaving, cream are usually provided with a screw type cap, and it is necessary to remove the cap each time the material is used. The removal and replacement of the screw type cap is an inconvenience, as the cap is sometimes dropped or misplaced, resulting in much delay and wasted eiiort. Furthermore, the screw type cap frequently becomes filled with the dispensed material, and is therefore unsanitary and dlflicultto manipulate.

In accordance with the practice of the present invention, a cap is provided which opens and permits extrusion of the material in the container upon application of pressure thereto. When the pressure against the container is relieved, the

aperture through the end of the resilient cap closes due to the centrally directed stressesin the resilient material of the cap. By this'method of closing the extrusion orifice, the flow of material from the container is cut off at the cap surface, and no further operation is required to effect closure of the container.

The objects and advantages of the present invention are obvious, in'vie'w of the construction of the cap described herein. For example, there is no cap to be removed or replaced; and it is more sanitary, more eilicient, andniore economical in that less of the material to be dispensed is wasted.

Reference may be had to the following description and to the accompanying drawing for a more detailed disclosure of the invention, its mode ofoperation, and the advantages obtained thereby.

In the drawing:

Fig. 1 is a side elevational'view, in section, of a dispensing cap embodying the features of our;

invention; I

Fig. 2 is an end view thereof, in section, taken along line II-II of Fig. 1%

Fig. 3 is a side elevational view, in section, of the cap attached to a dispensing container;

- Fig. 4 is a similar view illustrating the func- V tional features ,of the cap;

With reference to the drawing, and in particular to Figs. 1 and 2, we show an embodiment oi. the invention in the form of a cap having a tubular body I open at one end and closed at the other end. The body I is made of flexible, stretchable, resilient material, preferably a vulcanized, soft, elastic rubber composition. 'An end wall 2 is connected to the tubularside walls 2 by means of an intermediate portion 3-having a thickness less than that of the side walls 2. The end wall 2 is located in such manner that it lies wholly within the tubular portion 2 of the body l,,i. e. in a reentrant position. Preferably, the intermediate portion 3 forms a frustroconical outline in which the end having the smaller diameter unites with the end wall 2. A slit 4 extends through the wall member 2, and a depression 5 in the form of beveled surfaces adjacent the slit 4 is formed in the end wall 2 on the innermost side relativeto the tubular-body I.

The function or the resilient memberv is shown in thedrawing, with particular reference to Figs. .3 and 4. As shown in Fig. 3 the member is attached, through the medium of a ferrule 6 having threads 1, to a dispensing containerl. Such a dispensing container is or conventional form such as a tube having a flexible body made or material such as lead foil.

when the dispenser cap of our invention is applied to a container, and pressure is exerted upon the container, the dispensing material 9 is forced against the inner side of the end wall 2, with the result that the wall is carried outwardly as shown in Fig. 3. The relatively thin wall of the intermediate portion 3 permits outward movement of the wall 2 upon the application of pressure from within. As pressure is exerted against the dispensing material the end wall 2 becomes distended and the slit 4, which is normally in a closed state, opens to permit extrusion of the material 9 from the dispensing container. When manual pressure on the dispensing container is relieved, the end wall 2 and its adjacent portions return, at least in part, to their normal, un-

strains are set up in the end wall 2-. These compression stresses and strains result from the compression stresses present in the intermediate portion 3 when the intermediate portion becomes confined between the end wall 2 and the tubular body I during axial movement of the end wall 2 relative to the tubular body I. In this position, and as shown in Fig. 4, the compression stresses and strains present in the wall 2 cause the surfaces defining the slit 4 to move tightly together, thus shearing off a strip of the dispensed material lll. After the dispensing assembly remains in a state of rest for a short period, the cap usually returns to its normal, unstrained state, as shown in Fig. 1.

It is, therefore, apparent that in operation the dispensing assembly will function automatically 'in accordance with internal pressure exerted in the container. The slit I normally remains closed. and is opened only on the application of pressure against the container. When the pressure is relieved the dispensing cap, due to the stresses and strains formed therein, functions to shear oil the trailing end of the extruded material and the assembly needs no further attention.

This automatic opening and closing feature prevents waste of material to be dispensed, and obviates the necessity of the conventional practice of wiping the end of the cap in order to clear it of the dispensed material. As the dispensing slot is normally closed, the cap may be washed either before or after using, as by placing it under running water.

A modified embodiment. of the invention is shown in Figs. 5, 6 and 7. This modification of the invention contemplates the formation of a cap member shaped as a substantially tubular member ll open at one end and closed at the other end. The cap member is made of flexible, stretchable, resilient material, preferably a vulcanized rubber composition. The wall'forming the end of the cap member has portions of differis shown secured to a dispensing container ll. The annular ridge l6 engages in complementary relation with an annular indentation l8 (Fig. 7) at the cap end of the dispensing container. A metallic band. l9 may be forced or swaged into place, as shown in Figs. 6 and '7, so as to secur the dispensing cap in permanent engagement with the container. The band I! holds the ridge IS in engagement with the annular depression l8 at the can end gof the dispensing c ontainer, thereby preventing axial movement of the attaching end of the cap to the .cap end of the container.

An aperture may be made through the end wall l2 of the cap, either during the time of its manufacture or at any subsequent time. The preferred practice is to omit the aperture 20 in the manufacture of the cap, so that the cap will be fluid tight during such time as the dispensing container remains an unsold article. When it is first desired to utilize the material in the container, the user may slit or pierce the end wall I! with any common tool such as a knife or pin.

When an aperture is made intothe end wall of the cap, the tension stresses at the outer end portions of the cap produce compression stresses at the central end wall l2, thereby providing a direct force for maintaining the aperture 20 in a normally closed state. When pressure is exerted against the container H, the dispensing materialli is directed toward the cap, causing against the container is relieved, the tension at ent thickness. The central end wall portion l2 is of a thickness substantially less than its surrounding annular portion". Near the closed end of the cap member and internally of the member is a recess ll forming a thin, annular portion Ii in the side wall of the cap member.

On the outer wall of the tubular member H is an annular ridge l6, and having for its purpose to assist in securing the'cap 'member to a dispensing container, as hereinafter.more particularly described.

The resilient dispensing cap is molded and vulcanized as shown in Fig. 5. After vulcanization the resilient cap is removed from the mold and turned inside out as shown in Fig. 6. As a result of the cap member being turned inside out, deflnite stresses and strains are set up in the end portion of the cap. A portion of the tubular wall ll adjacent to the thin, annular portion I5 becomes extended radially due to the reversed position of the cap, with the result that those portions incur tension stresses and strains. The thin, annular portion l5 functions as a hinge around which the principal tubular wall portion of the cap bends in assuming its reverse or inside-out position. As a result of the tension strains formed by reversing the position of the cap, secondary stresses and strains are directed toward the end wall l2, thereby placing the rubber composition of'said wall in a state of compression.

Due to the reversal of the cap, the annular ridge It changes its position from the outer side the rim portions of the cap react to place the end wall It under compression, thereby closing the aperture 20. I

In the operation of the dispensing assembly it is obvious that the dispensing orifice will open and close automatically in accordance with the pressure exerted against the container. When the pressure against the container is relieved, the dispensing orifice in closing shears off the trailing end of the material extruded from the container.

It is to be understood that various degrees of tension and/or compression may be incorporated in the end-portion of the cap to-suit different conditions of density of the'plastic material in the dispensing container. While the cap is referred to as being composed of rubber, the principal requirement is that it should be of a flexible, stretchable, resilient nature, and therefore it is found that various synthetic rubbers, such -closure comprising a hollow body of flexible,

stretchable, resilient material; said body having side walls adapted to be connected to said container and .an end closure wall adapted to be pierced in its central portion to provide a discharge opening therein; said end wall being in a reentrant position in respect to said side walls when said closure is free from internal pressure; the central portion of said end wall being free from tension when in said reentrant position; said end wall being adapted to be flexed outwardly beyond the end of said side walls by internal pressure produced in said closure so as to cause any discharge opening that may be formed in said end wall to be opened up; and said end wall having stresses set up therein which cause it to return to its reentrant position when the closure is free from internal pressure.

2. A closure for a dispensing container adapted to have internal pressure formed therein; said closure comprising a hollow body oi. flexible, stretchable, resilient material; said body having side walls adapted to be connected to said con- A nected to said side walls by relatively thin flexible resilient material; said end wall being in a reentrant position in respect to said side walls when said closure is free from internal pressure; the central portion of'said end wall being free from tension when in said reentrant position; said end wall being adapted to be flexed outwardly beyond the end of said side walls by internal pressure produced in said closure so as to cause any dischargeopening that may be formed in said end wall to be opened up; and said end wall having stresses set up therein which cause it to return to its reentrant position when the closure is free from intemal pressure.

3. A closure for dispensing container adapted to have internal pressure formed therein; said closure comprising a hollow body of flexible, stretchable, resilient material; said body having side walls adapted to be com acted to said container and an end closure wall adapted to be pierced in its central portion to provide a discharge opening therein; said end wall being in a reentrant position inrespect to said side walls when said closure is free from internal pressure; the central portion of said end wall being free from tension when in said reentrant position; said end wall being adapted to be flexed outwardly beyond the end of said side walls and the central portion thereof placed under'tension by internal pressure produced in said closure so as to cause any discharge opening that may be formedin said end wall to be opened up; and said end wall having stresses .set up therein which cause it to return to its reentrant position when the closure is free from internal pressure.

l 4. A closure for a dispensing container adapted to have internal pressure formed therein; said outer end of said side wall when said closure is tree irom internal pressure; the central portion of said end wall having a slit like discharge opening which is closed when said end wall is in said reentrant position; said slit like opening having inwardly diverging walls and the outer edges of the walls of said opening being in contact when said end wall is in said reentrant position; the material around said opening being free from tension when said end wall is in said reentrant position; said end wall being adapted to be flexed outwardly beyond the end of said side walls by internal pressure produced in said closure so as to cause the walls of said discharged opening to separate; and said end wall being so constructed that stresses are set up in said material during the outward movement which caused the end wall to return to a reentrant position upon the release of the internal pressure within said closure.

5. A closure member for a dispensing container adapted to have internal pressure formed therein; said closure comprising a hollow body of flexible, stretchable, resilient material; said body having side walls adapted to be connected to said container and an end wall connected to said side walls and having a discharge opening formed therein; the central portion of said end wall being retained in a reentrant position with respect to the outer end of said side walls and under compression by tension stresses in the outer end of said side walls when said closure isfree from internal pressure, said end wall being adapted to be flexed outwardly beyond the end of said side walls and placed under tension by internal pressure produced in said closure so as to cause the walls of said discharge opening to separate to permit the discharge of material; and said stresses formed in the outer end of said side walls and said end wall being adapted to cause said end wall to return to its reentrant position when the closure is free from internal pressure.

6. In a dispensing device, the combination of a collapsible receptacle for plastic substances, and a cap of resilient material secured to the receptacle, said cap having cylindrical side walls and an end wall having an aperture extending therethrough, that portion of the cap lying adjacent the aperture being characterized by being held in a state of compression by that portion of the cap lying further away from the aperture, and the relationship between the cylindrical wall and the end wall being such that pressure of the plastic substance against the end wall causes compression stresses to occur in the end wall and subsequently causes tension stresses to occur in the end wall.

7. The method of making a self closing dispensing cap comprising the steps of forming the cap from resilient material so as to provide side walls and an end wall adapted to be provided with a slitted opening, and turning the capinside out and thereby placing the end wall in a state of compression.

8. The method 01 making a self closing dispensing cap comprising the steps of forming the cap from resilient material so as to provide an end wall having a slit-like opening formed therein and side walls of greater thickness than said end wall and having a ring of reduced thickness adjacent to the end wall, and turning the cap inside out and bending the side walls about the end wall at the ring of reduced thickness, and thereby placing the end wall in a state of compression.

ARTHUR w. BULL. cam: it. snow. common as. GRAFTON. 

